By Rich Sherman

“Perhaps, says DESI’s scientists, the density [of dark energy] is changing over time…. If the findings prove true, it would catapult cosmology into a crisis.” –The Economist

Every now and then there is an article that makes you stop. In June, The Economist published an article about startling preliminary results from the Dark Energy Spectroscopic Instrument (“DESI”) at Kitt Peak National Observatory. The preliminary results were published at the 2024 American Physical Society’s annual meeting. The data shows that dark energy has NOT been a constant—it became denser until about five billion years ago and is now weakening. If accurate, this creates great problems for the standard model of cosmology, for Einstein’s Theory of Relativity, and for the expected fate of the universe (bringing the possibility of the Big Crunch or the Big Rip back into the fray). 

In a club filled with scientists, doctorates and people with technical backgrounds, I would enjoy covering this topic at a future AAAP meeting.